Certain 6-trifluoromethylcytosines and thiocytosines,their synthesis,and their use in the synthesis of uracils and thiouracils

ABSTRACT

3-AMINO-2-SUBSTITUTED - 4,4,4 - TRIFLUORO-2-BUTENENITRILES ARE REACTED WITH ISOCYANATES OR ISOTHIOCYANATES IN THE PRESENCE OF AN INERT SOLVENT AND FROM 0.75 TO ABOUT 1.0 MOLE EQUIVALENTS OF STRONG BASE PER MOLE OF BUTENENITRILE TO PRODUCE THE NOVEL UREIDO BUTENENITRILES OF THE FORMULA:   CF3-C(-NH-C(=X)-NH-R)=C(-HALO)-CN   WHEREIN R IS ALKYL, ALKENYL, PHENYL, BENZYL AND SUBSTITUTED DERIVATIVES THEREOF AND X IS SULFUR OR OXYGEN. THE UREIDO BUTENENITRILE ARE TREATED WITH ADDITIONAL BASE TO PRODUCE NOVEL CYCLIC CYTOSINES OF THE FORMULA:   6-CF3,5-HALO,4-(HN=),3-R,2-(X=)-1,2,3,4-TETRAHYDRO-   PYRIMIDINE   WHEREIN R AND X ARE AS DEFINED ABOVE. THE CYTOSINES CAN BE PRODUCED DIRECTLY BY TREATING 3-AMINO-2-SUBSTITUTED4,4,4-TRIFLUORO-2-BUTENENITRILE WITH AT LEAST 1.0 MOLE EQUIVALENT OF BASE. THE NOVEL COMPOUNDS ARE USEFUL INTERMEDIATES IN THE PREPARATION OF HERBICIDAL URACILS AND THIOURACILS.

United S tates Patent ABSTRACT OF THE DISCLOSURE 3-amino-2-substituted 4,4,4 trifiuoro-Z-butenenitriles are reacted with isocyanates or isothiocyanates in the presence of an inert solvent and from 0.75 to about 1.0 mole equivalents of strong base per mole of butenenitrile to produce the novel ureido butenenitriles of the formula:

F;C-C=C (halo) ON NHFNHR wherein R is alkyl, alkenyl, phenyl, benzyl and substituted derivatives thereof and X is sulfur or oxygen. The ureido butenenitriles are treated with additional base to produce novel cyclic cytosines of the formula:

ii r20 x l N...

D'IH

wherein R and X are as defined above. The cytosines can be produced directly by treating 3-amino-2-substituted- 4,4,4-trifluoro-2-butenenitrile with at least 1.0 mole equivalent of base. The novel compounds are useful intermediates in the preparation of herbicidal uracils and thiouracils.

This application is a division of application Ser. No. 873,679, filed NOV. 3, 1969, now U.S. Pat. 3,635,977 (1972).

SUMMARY OF THE INVENTION Process This invention relates to a process for preparing novel substituted 6-(trifluoromethyl) cytosines (and tautomers thereof) of the formula:

wherein:

X is sulfur or oxygen;

R is selected from the group consisting of alkyl, alkenyl, phenyl, benzyl and substituted derivatives thereof; and

Y is selected from the group consisting of hydrogen,

chloro, bromo, and fluoro;

which comprises contacting a 3-amino-2-substituted-4,4,4- trifluoro-Z-butenenitrile of the formula:

F C(NH )C=C(Y)CN with a substituted isocyanate of the formula RNCX in the presence of base and an inert solvent wherein X, R, and Y are as defined above.

3,781,324 Patented Dec. 25, 1973 ice If the amount of base used is between about 0.75 and about 1.0 mole equivalent per mole of butenenitrile reactant, the principal product will be a novel ureido-4,4,4- trifluoro-Z-butenenitrile of the formula:

where X, Y, and R are as defined above.

When 1.0 or more moles of base are used, or when the Formula III compound is treated with additional base, cyclization occurs to yield novel cytosines and thiocytosines of the formula:

H N F3 -X Y N-R wherein X, Y, and R are as defined above.

Compounds This invention also relates to the two groups of novel compounds prepared by the heretofore described novel process of this invention. More particularly, this invention relates to novel ureido-4,4,4-trifluoro-2-butenenitrile compounds of the formula (IV) N H:

and to novel cytosine and thiocytosine compounds of the formula:

H N N me x no =2:

l Y N-R Y N-R H (W NH;

wherein X, R, and Y are as previously defined.

This invention also relates to the tautomers of the Formula IV compounds and to the water soluble salts, particularly the sodium, potassium, and ammonium salts, of the compounds and tautomers.

Utility of the compounds The ureido compounds (III) are useful as intermediates in the preparation of the cytosines and thiocytosines (IV) which, in turn, are useful intermediates in the prepara tion of herbicidal uracils and thiouracils when acid hydrolyzed in accordance with the following equation:

H H N F 0 X FaO -X I Y N-R acid, water Y N-R wherein X, R, and Y are as defined above.

The herbicidally elfective uracils and thiouracils (V) are described and claimed in the copending application for US. Letters Patent, Ser. No. 737,308, filed June 17, 1968, in which I am named as co-inventor. The herbicidal properties of the uracils are more fully exemplified in Examples 84 and 85 hereinbelow.

DEFINITIONS As used throughout this specification:

The term alkyl means straight and branched chain alkyl radicals having from 1 to 12 carbon atoms and cycloalkyl radicals having from 3 to 8 carbon atoms. Illustrative members are methyl, ethyl, isopropyl, n-butyl, tertiary butyl, hexyl, octyl, dodecyl, Z-methylhexyl, 2- 2-ethyl-3-methy1heptyl, 3,3-diethyloctyl and 2-ethyldecyl. Members such as cyclopropyl cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl are illustrative of the cycloalkyls referred to above.

The term alkenyl means unsaturated straight and branched chain hydrocarbons having from 2 to -6 carbon atoms; illustrative members include allyl, Z-butenyl, and 2-metha1lyl.

The terms substituted alky, substituted alkeny, substituted phenyl, and substituted benzyl mean that the basic radical may contain one or two substituents, either the same or difierent, selected from the group consisting of halogen, nitro, amino, lower alkyl, monohalo (lower) alkyl, polyhalo (lower) alkyl, lower alkoxy, carboxy and carb (lower) alkoxy. Illustrative members include Z-methoxyethyl, 3-ethoxypropyl, 2-bromopropyl, 3- chlorobutyl, 3-nitrophenyl, 2,3-dichlorophenyl, 2-carboxyphenyl, Z-carbometh'oxypropyl, 2-chloro 4 nitrophenyl, tolyl, 2,4-diaminophenyl, 2-chlorobenzyl, 3-bromo-2- methoxypropyl, ip-aminophenyl, m-trifluoromethylphenyl,

2,4-dichlorophenyl, and the like.

The term halogen means chloro, bromo, iodo, or fluoro.

The term lower alkyl means straight and branched chain alkyl radicals containing from 1 to 4 carbon atoms; illustrative members are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and t-butyl.

The term polyhalo means 2 to 4 halogens.

The term lower alkoxy means alkoxy radicals containing from 1 to 4 carbon atoms; illustrative members are methoxy, ethoxy, propoxy, and butoxy.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The Process Starting materials Certain of the 3-amino-Z-substituted-4,4,4-trifluoro-2- butenenitrile starting materials are described in the literature along with a process for their preparation. For example, accoding to Krespan [The Journal of Organic Chemistry, vol. 34, No. 1, 42-45 (1969)], said publication incorporated herein by reference, 2,3-dichlorohexafiuoro-Z-butene can be treated with ammonia replacing a chlorine to form 2-amino-3-chloro-1,1,1-4,4,4-hexafiuoro-Z-butene c1=, 1-m,,)o= c c1 cF Reaction of this product at 50 with ammonia then yields the starting material 3-amino-2-chloro-4,4,4-trifluoro-2- butenenitrile:

Similarly, the starting material 3-amino-2,4,4,4-tetrafluoro-2-butenenitrile can be prepared from octafluoro-Z-butene by reaction with ammonia to form 1-(trifluoromethyl)-2,3,3,3-tetrafiuoropropylidenimine. Reaction of this product with ammonia yields the desired butenenitrile referred to above.

The preparation of starting material, 3-amino-4,4,4- tetrafluorocrotonitrile, as represented by the formula:

is readily prepared by reacting 2-amino-1,1,1,4,4,4- hexafluoro-Z-butene with pressurized ammonia as taught by Krespan in his heretofore cited article.

The X and R substituents are provided by the reactant isocyanate, RNCX. The isocyanate compounds required to produce the designated R and X substituents are all either readily available or can be readily prepared in accordance with procedures well known to those skilled in the art and which do not bear repeating herein.

The above described reactants may be directly cyclized to useful herbicidal cytosines and uracils or they may first be converted to analogous or homologous butenenitriles and then cyclized to useful cytosines and uracils.

Reaction conditions (a) Temperature and pressure: The reaction may be carried out over a temperature range from about 0 C. to about 60 C. and preferably at a temperature between about 15 C. and 50 C.

The reaction can be run at subatmospheric, atmospheric, or superatmospheric pressures, with atmospheric pressure preferred.

(b) Solvents: Among the solvents which find utility in the present process are aromatic solvents having from 6 to 8 carbon atoms including the monocyclic aromatics and halogenated aromatics such as toluene, benzene, xylene, and chlorobenzene; the lower alcohols having from 1 to 8 carbon atoms including methyl, ethyl, propyl, isopropyl, amyl, isoamyl, pentyl, octyl, t-butyl and hexyl alcohol: low molecular weight glycol ethers having a molecular weight below about 200: illustrative of these ethers are diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and ethylene glycol dimethyl ether; and dipolar aprotic solvents which have a coordinated valence link between two originally neutral atoms whereby one loses and the other gains a share of two electrons and which neither yields a proton to the solute, nor gains one from it. These latter solvents include, dimethylsulfoxide, dimethylformamide, acetone, methylisobutyl ketone, acetonitrile, nitrobenzene, N,N-dimethylacetamide and tetrahydrosulfolanes.

(c) Isocyanate/butenenitrile ratio: The mole ratio of isocyanate or isothiocyanate to butenenitrile is preferably 1 to 1 although a ratio of 2 to 1 may be used effectively.

(d) Bases: A strong base is essential to the reaction and is preferably selected from the group consisting of alkali metal alkoxides such as potassium tertiary butoxide,

sodium methoxide, sodium propoxide; alkali metal hyt droxides such as sodium hydroxide, potassium hydroxide and the like; and alkali metal hydrides such as potassium, sodium, and lithium hydride. In practice, about 1.0 or more mole equivalents of base, usually about 1 to 3 mole equivalents and preferably about 2 mole equivalents of base per mole of butenenitrile is required to achieve cyclization. Of course, as much base as desired may be used limited only by economics. When the reaction is conducted as described above but only about 0.75 to about 1.0 mole equivalents of base are used, it has been found that no substantial cyclization of the 3-aminobutenenitrile (II) to the cytosine (IV) is achieved and the predominance of product formed is a 3-substituted ureidobutenenitrile (III) corresponding in the 2 and 4 positions to the starting material. When the thus formed ureido compound is treated with additional base, cyclization occurs and the desired cytosine is formed. These re.-'' actions may be graphically shown as follows:

solvent CH3C=C (Y) C N CH: (NHa) C=C (Y) ON .75 to about 1.0 mole NHONHR (II) equivalent base II 1.0 or more mole III equivalent of base\ additional 1 base H N FaC X Y N-R H (IV) The Compounds The following are illustrative of the novel cytosines and thiocytosine compounds of the invention:

3-methyl-5-bromo-6-(trifluoromethyl)cytosine 3-propyl-5-bromo-6-(trifluoromethyl)cytosine 3 -nonyl--fluoro-6- (trifluoromethyl) cytosine 3-dodecyl-5-bromo-6-(trifluoromethyl)cytosine 3-cyclopropy1-5-chloro-6- (trifluoromethyl) cytosine 3-cyclohexyl-5-fluoro-6- (trifluoromethyl) cytosine 3-cyclobutyl-5-chloro-6-(trifiuoromethyl)cytosine 3-isopropyl-6-(trifluoromethyDcytosine 3-decyl-6-(trifiuoromethyl)cytosine 3-cyclopenty1-6-(trifluoromethyDcytosine 3- (2-butenyl) -6- (trifluoromethyl) cytosine 3-allyl-6- (trifiuoromethyl) cytosine 3-benzy1- 6- (trifluoromethyl) cytosine 3-phenyl-6-(trifluoromethyDcytosine 3- (4-chlorobutyl) -6- (trifluoromethyl) cytosine 3-(1-eth'ylpropyl)-6-(trifluoromethyl)cytosine 3-(3-bromo-2-methoxypropyl)-6- (trifluoromethyl) cytosine 3- (m-trifluoromethylphenyl)-6- (trifluoromethyDcytosine 3 2,4-dichlorophenyl) -6- (trifluoromethyl) cytosine 3- (tolyl) -6-(trifluoromethyl) cytosine 3-(2-carbomethoxypropyl)-6-(trifluoromethyDcytosine 3-ethyl-S-bromo-6-trifluoromethyl-Z-thiocytosine 3-butyl-5-fluoro-6-trifluoromethyl-Z-thiocytosine 3-pentyl-5-chloro-6-trifluoromethyl-2-thiocytosine 3-octyl-5-chloro-6-trifluoromethyl-2-thiocytosine 3-undecyl-S-fluoro-6-trifluoromethyl-2-thiocytosine 3-(p-carboxyphenyl)-5-fluoro-6-trifluoromethyl-2-thiocytosine 3-(2,4-dichlorophenyl)-5-chloro-6-trifluoromethyl-2- thiocytosine 3- l-ethylpropyl-S-bromo-6-trifluoromethyl-2-thiocytosine 3-isopropyl-6-trifluoromethyl-2-thiocytosine 3-(t-butyl)-6-trifluoromethyl-2-thiocytosine 3-heptyl-6-trifiuoromethyl-Z-thiocytosine 3-cycloheptyl-6-trifluoromethyl-2-thiocytosine 3-(Z-methylallyl)-6-trifluoromethyl-Z-thiocytosine 3-benzyl-6-trifluoromethyl-2-thiocytosine 3-phenyl-G-trifluoromethyl-Z-thiocytosine 3-( l-ethylpropyl) -6-trifluoromethyl-2-thiocytosine 3-( 3-rnethoxypropyl)-6-triflu0romethy1-2-thiocytosine 3-(2,3-dibromopropyl)-6-trifiuoromethyl-Z-thiocytosine 3-(p-carboxyphenyl)-6-trifluoromethyl-Z-thiocytosine 3-tolyl-6-trifiuoromethyl-2-thiocytosine 3-(3,4-dichlorophenyl)-6-trifluoromethyl-2-thiocytosine The following are illustrative of the novel ureido-4,4,4- trifluoro-Z-butcnenitrile compounds of this invention. 1-[2-cyano-2-bromo-1-(trifluoromethyl)-vinyl]- 3-methylurea 1-[2-cyano-2-bromo-l-(trifluoromethyl)-vinyl]- 3-propylurea 1-[2-cyano-2-bromo-1-(trifluoromethyl)-vinyl]- 3-nonylurea.

1-[2-cyano-2-bromo-l-(trifluoromethyl)-vinyl]- 3-dodecylurea 1- [2-cyano-2-bromo-1-(trifluoromethyl)-vinyl]- 3-cyclopropylurea. 1-[2-cyano-2-bromo-l-(trifluoromethyl)-vinyl]- 3-cyclohexylurea 1-[2-cyano-2-bromo-1-(trifiuoromethyl)-vinyl]- 3-cyclobutylurea 1- [Z-cyano- 1- (trifluoromethyl vinyl] -3-cyclopentylurea 1-[2-cyano-1-(trifiuoromethyl)vinyl]-3-(2-butenyl)urea 1-[Z-cyano-1-(trifinoromethyl)vinyl]-3-benzylurea 1-[2-cyano-1-(trifluoromethyl)vinyl]-3-phenylurea 1- [Z-cyano- 1- (trifluoromethyl)vinyl]-3 (4-chlorobutyl)urea 1- [2-cyano-1- (trifluoromethyl)vinyl] -3 l-ethylpropyl)urea 1-[Z-cyano-1-(trifluoromethyl)vinyl]-3-(3-bromo- 2-methoxypropyl)urea 1-[2-cyano-1-(triiiuoromethyl)viny1]-3-(2,4-dichloropheny1)urea 1-[Z-cyano-l-(trifluoromethyl)vinyl]-3-(2-carbomethoxypropyDurea 1- [2-cyano-2-bromo- 1- (trifluoromethyl) vinyl] -3-ethylurea 1- [2-cyano-2-fluoro- 1- (trifluoromethyl) vinyl] -3-butylurea 1- [Z-cyano-Z-chloro- 1- (trifluoromethyl) vinyl] -3 -pentylurea 1-[2-cyano-2-chloro-1-(trifluoromethyl)vinyl]-3-octylurea 1- [Z-cyano- 1- (trifluoromethyl vinyl] -3- (p-carboxyphenyl)urea 1- [Z-cyano- 1- (trifiuoromethyl vinyl] -3- 2,4-dichlorophenyl)urea 1- 2-cyano-1- (trifluoromethyl) vinyl] -3-( l-ethylpropyl- 2-bromo)urea 1-[Z-cyano-1-(trifiuoromethyl)vinyl]-3-isopropylurea 1- 2-cyano- 1 trifiuoromethyl vinyl] -3 (t-butyl urea 1- [Z-cyano- 1- (trifluoromethyl) vinyl] -3-heptylurea 1-[2-cyano-1-(trifluoromethyl)vinyl]-3-cycloheptylurea 1-[2-cyano-1-(trifluoromethy1)viny1]-3-phenylurea 1- [Z-cyano- 1- (trifluoromethyl) vinyl] -3- l-ethylpropyl)urea 1- [Z-cyano- 1- trifluoromethyl vinyl] -3- (3 -methoxypropyl)urea 1-[2-cyano-1-(trifluoromethyl)vinyl]-3-(2,3-dibromopropyl)urea 1-[Z-cyano-l-(trifluoromethyl)vinyl]-3-(p-carboxyphenyl)urea 1-[Z-cyano-l-(trifiuoromethyl)vinyl]-3-tolylurea 1-[Z-cyano-l-(trifluoromethyl)vinyl]-3-(3,4-dichlorophenyl)urea Advantageously, the herbicidal compounds, prepared in accordance with the process of the present invention, may be formulated with conventional carriers and applied with conventional type application equipment. For example, the active compounds may be formulated as dusts, dust concentrates, emulsifiable concentrates, wettable powders and the like.

Wettable powder formulations are generally prepared by admixing from about 25% to about by weight, of active ingredient with finely ground clay, such as kaolin or attapulgite. Generally about 3% to 10% by weight of a surface active agent is added. Alkali metal lignosulfonates, calcium salts of alkyl, aryl, sulfonic acid, sodium isothionate and alkyl phenoxy polyethylene ethanol are illustrative of such agents. The formulation is then dispersed in water for spray application.

Dusts and dust concentrates are similarly prepared using from about 5% to about 95% of active ingredient and from about 95 to about 5% of finely divided inert ingredients. These dusts are generally applied as such, or they may be further diluted with finely ground inert solids and then applied with conventional dusting apparatus.

Emulsifiable concentrates may be prepared by dissolving or dispersing the active ingredient in organic solvent, with about 3% to 10% by weight of an emulsifying agent, a surfactant, as described above, or the like. Such formulations are then diluted with either water or an appropriate organic diluent prior to application.

The following examples are provided to further illustrate the invention.

EXAMPLE 1 01 i N-CaH1-l 3-amino-2-chloro4,4,4-trifiuoro 2 butenenitrile (7.0 g., 41 mmoles) was added in a dropwise manner to a stirred solution of potassium-tert-butoxide (4.6 g., 41 mmoles) in 25 ml. of dimethylsulfoxide while maintaining the temperature at 20 C. Isopropylisocyanate (4.0 g., 47 mmole) was then added with stirring with the tem perature at 20 C. After one-half hour another 41 mmoles of base were added and the solution was stirred for an additional one-half hour. The reaction solution was poured into water (50 ml.) and this solution extracted with ether. The aqueous phase upon acidification deposited a solid (8.5 g., 81% yield). Recrystallization from chloroform gave the product as a white solid with M.P. 218-220 C.

EXAMPLE 2 Preparation of -chloro-3-isopropyl- 6- trifluoromethyl) thiocyto sine N FsC -S Ila 3-arnino-2-chloro-4,4,4-trifluoro-2-butenenitrile (7.0 g.) is added dropwise to a stirred solution of potassium-tertbutoxide (4.6 g.) in 25 ml of dimethylsulfoxide while maintaining the temperature at 20 C. Isopropylisothiocyanate (4 g.) is then added and the stirred solution is maintained at 20 C. To this mixture is then added an additional 4.6 g. of potassium-tert-butoxide and the resulting solution poured over ice. This mixture is extracted with ethyl ether and the remaining aqueous phase acidified with HCl to yield 5-chloro-3-isopropyl-6-(trifiuorometh- The above compound was prepared following substantially the same procedure as in Example 1 except that 3 amino-2-chloro-4,4,4-trifluoro-2-butenenitrile was replaced by 3-amino2-bromo-4,4,4-trifluoro-2-butenenitrile.

EXAMPLES 4 to 22 Following substantially the same procedures as in Examples 1, 2, or 3 except that the isocyanate and/or the number 2 substituent on the butenenitrile compound were varied, a variety of cytosines were prepared as shown in Table I below:

TABLE 1 it FaC(NHz)G=C(Y)ON RNCX M new x Y N-R Example X Y R Br CH: Br C2115 Br 11-0311! 01 l'l-C4H0 Br sec-C4110 Br n-CrzHzs Br 11-0311 Br 14 0 Br CHzCOOCzHs 15 0 Cl CH:

Cfi-(CzHs):

16 0 Cl CHzCH=CHl 17 S Bl 19-....1:::-.. 0 Br Br Br --CHz( JHCH:

20 S Cl -CH:CH2CH:

OCH:

EXAMPLE 23 Preparation of 3-isopropyl-5-fluoro-6-(trifluoromethyl) cytosine l? or. =o

F NCH( Ha):

I NH

3-amino-2,4,4,4-tetrafluorocrotonitrile as prepared by Krespan in J. Org. Chem. 34, 42 (1969) (7.0 g., .045 mole) was added to a suspension of sodium methoxide (2.45 g., 0.045 mole) in DMF at 25-30 C. Isopropyl isocyanate (3.83 g., .045 mole) was added, the temperature not exceeding 30 C. The solution was then heated to about 50 C. for 0.5 hr.; then it was allowed to cool to room temperature and excess sodium methoxide (2.45 g.,

EXAMPLES 24 to 32 Following substantially the same procedure as in Example 23 except replacing isopropylcyanate with various isocyanate compounds, the compounds shown below in Table H were prepared.

TABLE 11 H N NE, om- W=x cr, :=crcN RNCX F Example 32 s oflzoooolm EXAMPLE 33 Preparation of 3-amino-4,4,4-trifluor0-2-butenenitrile NH: oFaiJ=oHCN EXAMPLE 34 Preparation of 3-isopropyl-6-(trifluoromethyl)cytosine CF; -O

The above compound was prepared following substantially the same procedure as that given in Example 1 except that 3amino-2-chloro-4,4,4-trifluoro-2-butenenitrile was replaced with the 3-amino-4,4,4-trifluoro-2-butene- 10 nitrile prepared in Example 33 to yield a product having a melting point of 233-235 C.

Analysis.-Ca1cd. for C H F N 0 (percent): C, 43.44; H, 4.56; F, 25.77; N, 19.00. Found (percent): C, 43.61; H, 4.42; F, 25.91; N, 18.93.

EXAMPLES 35 TO 49 Following substantially the same procedure as in Example 34 but replacing isopropylisocyanate with various other isocyanates, the compounds shown below in Table III were prepared.

TABLE III Example X R Preparation of 1-[2[cyano-Z-fluoro-l-(trifiuoromethyl)-vinyl]-3-isopropylurea CFsC=CFCN HNCONHCH(CH1)2 3-arnino-2,4,4,4-tetrafluoro-2-butenenitrile was added to a suspension of sodium methoxide (0.35 g., .0065 mole) in DMF at 20 C. Isopropylisocyanate (0.55 g. 0.0065 mole) was added with cooling. The reaction was maintained at this temperature for 2 hours, then poured into water which was extracted with ether and then acidified to pH 2 with cone. HCl. A brown oil formed which solidified to a tan solid (melting point 142145 C.) after several hours. The infrared and N.M.R. spectra supported the proposed structure.

C H F N 'O requires (percent): C, 40.18; H, 3.79; F, 31.77; N, 17.5. Found (percent): C, 40.23; H, 3.82; F, 31.58; N, 16.95.

EXAMPLE 51 Preparation of 1- [Z-cyano- 1- (trifluoromethyl) vinyl] -3-isopropylurea.

CHaC=C HON EN 0 O N(HCHs)a The above compound was prepared following substantially the same procedure as in Example 50 except that 3- amino 2,4,4,4 tetrafluoro 2 butenenitrile was replaced with the 3 amino 4,4,4 trifluoro-Z-butenenitrile prepared in Example 33; M.P. 156-157 C.

Analysis.-Calcd. for C H F N O (percent): C, 40.30; H, 5.06; F, 23.85; Found (percent): C, 40.72; H, 4.26; F, 23.80; N, 17.68.

EXAMPLES 52' To 67 Preparation of 1- [2-cyano-2-chloro-1-(trifluoromethyl)-vinyl-3-isopropylurea CF:C=C(C1)CN 3 amino-2-chloro-4,4,4-trifluoro-2-butenenitrile (0.05 mole) is admixed with a solution of (0.05 mole) of sodium methoxide in 50 ml. of dimethylsulfoxide. The reaction mixture is maintained at 40 C. and 0.07 moleof isopropylisocyanate is added with continuous stirring. The mixture is then poured into ice water and extracted with diethylether. The aqueous phase is acidified with hydrochloric acid yielding the named product.

The reaction product was worked up as described heretofore and recrystallized from ethanol-water yielding the above described product having a melting point of 162-164 C. By warming this ureido compound in methanol containing an equivalent of sodium methoxide, the cyclic compound, 5 chloro 3 isopropyl-6-(trifluoromethyl) cytosine, is obtained.

Any of the substituted ureido-4,4,4-trifluro-2-butenenitrile compounds of this invention can be prepared by merely following the procedures of Examples 50 to 52 except that the reactant isocyanate and Z-butenenitrile are varied as desired. In accordance with such procedures the compounds shown below in Table IV were prepared.

TABLE IV 1 mole of base FsC(NH:)C=C(Y)CN-l-RNCX CFa-C=C(Y)CN NHCNHR Example Y X R 53 Cl 0 CH: 54 C1 0 CH2OH=CH1 55 Br 0 n-CnHza Q 59 F 8 Cl CHzCHCHz 63 H S sec-C4 9 CHaCOC2 s 65 H O CH1CH=CH EXAMPLES 68 TO 81 Preparation of 5-chloro-3-isopropyl-6- (trifluoromethyl)uracil TABLE V a T acid H10 x l I Y N-R Y R Uracil melting point x Y 0.)

0 Br 212-21s.5 0 Br 197-198 0 Br 169-172 0 Cl 138-130 0 Br 130-132 0 Br 101-102 0 Br 98101.5

0 Br 239-24o.5

79 CHzCOOCzH5 O B! 185-188 so 3H1 0 01 2138-139 81 3H1 0 Cl 103-106 CH(02H5)2 EXAMPLE 82 Preparation of 5-fluoro-3-isopropyl-6- (trifluoromethyl)uracil l a r. om =o or; o

i I HCl(aq.) F N- aH7-l F N-CaHr-l 14 fluoro-3-isopropyl-6-trifluoromethyl) cytosine is replaced Herbitoxicity index by those of Examples 24 to 9=100% reduction in stand EX MP 9'':1 or 2 stunted plants remaining Preparation of 3-isopropyl-6-(trifiuoromethyDuracil 5 g=%-gg rggi i gi s tgga 6=:60-70% reduction in stand H H 5 =50-60% reduction in stand OF N OFS N =40-50% reductioninstand 3 H01 I T 10 3 =30-40% reduction in stand N-CiHT-l N-Crflz-l 2J=2030% reduction in stand 1=10-20% reduction in stand 0=No apparent eifect a1=abnorma1, malformed, twisted c=chlorotic g=unusnal physiological efiect The above uracil with M.P. 139-142" C. was prepared l 'y following the procedure of Example 82 except that 5- g f fluoro-3-isopropyl-6-(-trifiuoromethyl) cytosine was res=sevefe 1 placed with the compound of Example 34. t=tface to slight 1 A variety of such uracils were prepared using this pro- '=1 0 test cedure but wherein the compounds of Example 34 is re- Abbreviations for th e plant species employed 111 the placed by those of Examples 35 to herbicidal activity tests are as follows:

EXAMPLE 84 Rag=Ragweed Pre-emergence herbicidal activity La=Lambsquarters The pre-emergence herbicidal activity of uracils and Mu=Mustard thiouracils prepared from the novel intermediates of this Pi=Pigweed invention is provided below. Ba=Barnyard grass In these tests seeds of a variety of monocotyledonous C =c b and dicotyledonous plants are separately mixed with pot- GF=G foxtail ting soil and planted on top of approximately one inch WQ=Wi1d t of potting soil in separate pint cups. After planting, the Con=C cups are sprayed with an aqueous-acetone solution conc t=c tt taining test compound in sufiicient quantity to provide the Soy=Soybeans desired equivalent of four pounds per acre of test com- SB=Sugar b t pound per cup. The treated cups are then placed on green- AW=A11igator d house benches and cared for in accordance with green- BW=Bindw d house procedures. Three weeks after treatment, the tests CT =Canada thistle are terminated and each cup is examined and rated ac- JG=Johnson grass cording to the Herbitoxicity Index given below. The NS=Nutsedge results of these tests are presented in Table IV below. QG=Quackgrass TABLE VI.PRE-EMERGENCE HERBICIDAL ACTIVITY DATA-DOSAGE 4 LBJACRE H N FaC X l N-R X Y R Rag K0 La Mu Pi Ba Or GF W0 Cor Cot; Soy SB CH 9 9 7g 9 3 t H, 9 9 9 9 9 9 9 9 9 n-CaH 9 9 9 9 9 9 5 9 3 9 i-C3H 9 9 9 9 9 9- tg 7 7 9 n-C4H 9- 3 ti; 8 0 0 0 t 0 3 see-CE! 9 9 9e 9e 9 9c 9 s tg 9 11-C H 0 fig 3g 0 0 ,0 0 t 0 0 n-C12Hz5 9 9 0 9 0 0 mg 0 9 7 9- 9- 9 3g tg 3g 0 0 0 0 0 3 Q 9 9 9 9 mg mg mg 9 mg 9 9 9 O B1 C1 tg mg 9- 0 9 mg tg O 0 0 O 5 9 9 9 9 9 9 9 9 4g 9 9a 9 8 9 9 5g tg 4g 3g ta sec-0411a 9 9 9 9 9 9 9 8 In 9 mg 9 CHz(|'|JOCzHs 5 9 tg 9- 6 9 9 o o o 1 SOY 001' Got GF wo TABLE TI-Continued La Mu Bag 099999 ob b go r bomao 0W.

F HHHHHH HH tone/water mixtures in suflicient quantity to produce the 30 desired concentrations of about four pounds per acre of active compound when applied to the plants through a EXAMPLE 85 Post-emergence herbicidal activi The postthiouracils prepared from the novel P emergence herbicidal activity of uracils and spray nozzle operating at 30 p.s.i. for a predetermined intermediates of the time. After spraying, the plants are placed on greenhouse resent invention is demonstrated by treating a variety benches and are cared for in the usual manner, comof monocotyledonous and dicotyledonous plants 'with the 35 mensurate with conventional greenhouse practices. T wo compounds dispersed in aqueous-acetone mixtures. In the weeks after treatment, the seedling plants are examined test, seedling plants are grown in jiffy flats for about two and rated in Table VII below according to the Herbiweeks. The test compounds are dispersed in 50/50 acetoxicity Index provided above.

La Mu 9 antra- NB QG Bag TABLE VIL-POST-EMERGENCE HERBICIDAL ACTIVITY-4 LBSJACRE ACTIVE INGREDIENT l-C H1 11-C4Hl sec-CAI, CHEGBKIJH 1L1 Br 7; B! CHICOOCZHI O...'- Br 01 0... Cl 0-.- Cl 0... 01

O.;. Br

tt-o o om 5tt99890999999t0 9999 o 73 r o 9 S99999m 999999 g OOOtBm n ooottt oottoooo OOOt m n009O w00 9t9999 99999t0 TABLE VIP-Continued x Y R AW BW CT JG NS QG Rag K0 La Mu Pi Ba Cr or W0 0... H 0 9r 9 0 0 0 9 9 9 9 7 8 9 t o--. H Q 99 9 9 t 9 t 9 9 9 9 9 9 9 9 o-. H 01 o 9 9 t o 9 9 9 9 m 9- s 9 a 0... H to 9 9 o o o 9 9- 9 9 9- 9 9 9 ornoocin.

o-.. H CHzCH=OHz to 9 9 9 9 o 9 9 9 9 9 9 9 9 S H i-C9H m 9 9 0 0 0 9 9 9 9 9 9 9' 9" I claim: 1. A substituted ureido 4,4,4-trifluoro 2 butenenitrile compound of the formula:

FIG-0:0 (Y) ON NHCNHR wherein: X is selected from the group consisting of sulfur or oxygen;

Y is selected from the group consisting of hydrogen,

chloro, bromo, and fluoro;

R is selected from the group consisting of alkyl of 1 to 12 carbon atoms, alkenyl of 2 to 6 carbon atoms, phenyl, benzyl, and the substituted derivatives thereof, wherein said substituted alkyl, alkenyl, phenyl, or benzyl has 1 or 2 substituents selected from the group consisting of halogen, nitro, amino, lower alkyl of 1 to 4 carbon atoms, monohalo(lower)alkyl of 1 to 4 carbon atoms, polyhalo(lower)alkyl of 2 to 4 halogens and 1 to 4 carbon atoms, lower al'koxy of 1 to 4 carbon atoms, carboxy and carb(lower)a1koxy of 1 to 4 carbons.

2. A compound according to claim 1 wherein Y is selected from the group consisting of hydrogen, chloro,

20 and fluoro.

References Cited UNITED STATES PATENTS 2,729,669 1/1956 Papesch et a1. 260465.4 25 3,242,208 3/1966 Martin 260-465 D X 3,488,376 1/1970 Ulrich 260-465 D X OTHER REFERENCES Degering: An Outline of Org. Nitrogen Comps. (1945), 30 Univ. Lithoprinters, Ypsilanti, Mich., pp. 550 and 553.

Noller: Chem. of Org. Comps. (1957), 2nd ed., W. B.

Szrnant: Org. Chem,

JOSEPH PAUL BRUST, Primary Examiner US. Cl. X.R. 

